Exhaust feedback and control system for internal combustion engines

ABSTRACT

An exhaust feedback and control system for internal combustion engines. At least one feedback pipe is connected at one end to the engine exhaust pipe and at the other end to the engine intake for diverting a fractional portion of the engine exhaust and delivering it to the combustion chamber. An air pipe is connected to the engine air pump for delivering air under pressure through at least one passage to the exhaust pipe at a location in juxtaposition with the feedback pipe for diluting the fractional portions of diverted exhaust with air. The arrangement also provides for cooling of the exhaust and for damping pressure variations in the feedback line. A muffler-filter is interposed between the exhaust pipe and tail pipe.

I United States vPatent [151 3,672,340 Bomba [4 1 June 27, 1972 [s41 EXHAUST FEEDBACK AND CONTROL 1,921,783 8/1933 Schneider ..60/3O L SYSTEM FOR INTERNAL 3,500,807 3/1970 Daigh ..l23/1 19 A COMBUSTION ENGINES Primary Examiner-Wendell E. Burns [72] Inventor: Georg A. Bombs, Concord, Calif. Attorney-Townsend and Townsend [73] Asslgnee: Sliced-egg Walker, Berkeley, Calif. a part ABSTRACT An exhaust feedback and control system for internal com- [22] Flled' May 1970 bustion engines. At least one feedback pipe is connected at [2l 1 Appl. N0.: 38,278 one end to the engine exhaust pipe and at the other end to the engine intake for diverting a fractional portion of the engine exhaust and delivering it to the combustion chamber. An air p p is connected to the engine air p p for delivering air under pressure through at least one passage to the exhaust [58] Field of Search ..l23/1 19 A, l 19, 60/30 L p p at a location in juxtaposition with the feedback p p for diluting the fractional portions of diverted exhaust with air, [56] References Cited The arrangement also provides for cooling of the exhaust and UNITED STATES PATENTS for damping pressure variations in the feedback line. A muffler-filter is interposed between the exhaust pipe and tail pipe. 873,785 l2/l907 Reichel ....60/30 L 1,421,432 7/1922 Embank ..60/30 L 18 Claims, 5 Drawing Figures PATEHTEDJUW 1972 3,572,340

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sum 2 or 2 SPARKPLUG INLE INVENTOR. GEORG A. BOMBA WMW ATTORNEYS I INTAKE VALVE EXHAUST FEEDBACK AND CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES This invention relates to a new and improved exhaust emission and control system for internal combustion engines.

As gasoline is burned in the conventional internal combustion engine, carbon monoxide, hydrocarbons, and unburned gasoline is transmitted through the exhaust pipe to the atmosphere. It is an object of the present invention to eliminate such emissions from internal combustion engines while increasing engine mileage or emciency.

In order to accomplish these results, the present invention contemplates a novel exhaust feedback system for cooling engine exhaust, diluting the exhaust with air and directing a fractional portion of the engine exhaust and air mixture back to the engine for reburning.

In one form, the invention contemplates providing at least one feedback pipe connected at one end to the engine exhaust pipe and at the other end to the engine intake for diverting a fractional portion of the engine exhaust and directing it back to the combustionchamber. An air pipe is connected at one ends to the outlet of the engine air pump for delivering air under pressure and at its other end to the exhaust pipe in juxtaposition with the feedback pipe. A feature and advantage of this arrangement is that the increased pipe length and introduced air stream serve to coolthe exhaust, condensing unburned fuel into droplets and generally reducing activity in the exhaust gases. Separate cooling jackets or heat exchangers can also be provided around the exhaust path. The introduced air also serves to support complete combustion of the exhaust emissions upon recycling into the combustion chamber.

The invention-also contemplates means for damping pressure variations in the exhaust feedback line caused by acceleration and deceleration in the engine comprising a cavity in the feedback line formed for example by a pipe of larger diameter than the feedback pipe to provide a cavity or reservoir for damping pressure variations. A return pipe leads from the enlarged pipe or reservoir in the feedback line to the combustion chamber and can be connected in one of a variety of places, for example, upstream or downstream from the carburetor, the intake manifold or directly into the cylinder combustion chamber.

In a preferred embodiment the invention is applicable for automobile and diesel engines having a plurality of combustion chambers, an exhaust pipe, and an air pump. A plurality of feedback pipes are connected atone end to the exhaust pipe for diverting fractional portions of the exhaust, each of the feedback pipes having a cross-sectional area less than cross-sectional area of the exhaust pipe. The feedback pipes respectively terminate in a reservoir pipe which forms a cavity for damping variations in pressure in the feedback exhaust, and a return pipe directs exhaust feedback from the reservoir pipe to the combustion chambers of the engine. The feedback exhaust is diluted with air delivered by an air supply pipe having at one end a plurality of passageways connected to the exhaust pipe in juxtaposition with the feedback pipe connections. The other end of the air supply pipe is connected to the engine air pump for delivering air under pressure.

A feature and advantage of this arrangement is that the air delivered into the exhaust stream, and the arrangement of pipes in the feedback line, cool the exhaust, condensing the unburned fuel into droplets and reducing particle activity in the exhaust. In a preferred arrangement, the pipes are dimensioned so that the total fractional portion of diverted exhaust comprises approximately one-half to two-thirds of the exhaust and the exhaust is diluted with air in the ratio of approximately 1:].

The return pipe in the exhaust feedback line is preferably directly connected by a back pressure valve to the combustion chamber of the engine and in the case of a plurality of combustion chambers the return pipe terminates in a plurality of passageways respectively connected to the combustion chambers through back pressure valves, such as quick check valves.

The invention thus generally contemplates an exhaust feedback and control system for internal combustion engines comprising means for cooling the engine exhaust, means for diluting the engine exhaust with air, and feedback means for diverting a fractional portion of the air and exhaust mixture and directing the fractional portion back to the engine combustion chambers.

In order to further control exhaust emission the invention also contemplates the provision of a liquid mufi'ler-filter in the exhaust pipe line downstream from the feedback pipe connections. The liquid muffler-filter is formed generally with a tank having a liquid boiler compound-water mixture filling the tank to approximately, for example, two-thirds of its capacity. The exhaust pipe is connected to the tank below the liquid level in the tank so that the exhaust bubbles through the boiler compound-water mixture convering carbon monoxide to carbon dioxide. A tail pipe is connected to the tank above the liquid level in the tank for venting the exhaust after it has bubbled through the liquid compound in the tank. The combination of exhaust feedback and liquid muffler filtering effectively eliminates substantially all the noxious components otherwise found in internal combustion engine exhaust.

Other objects, features and advantages of the present invention will become apparent in the following specification and accompanying drawings.

FIG. 1 is a diagrammatic plan view of the exhaust feedback and control system.

FIG. 2 is a diagrammatic side view of the exhaust feedback and control system.

FIG. 3 is a detailed fragmentary diagrammatic view showing the return pipe connections to the engine in a preferred embodiment and FIG. 3a is a detailed diagrammatic view of the direct feedback into the combustion chamber through a back pressure valve.

FIG. 4 is a diagrammatic side view of the filter.

Referring to the embodiment of the present invention illustrated in FIGS. 1 and 2, the exhaust pipe 11 extending from the exhaust manifold of engine block 12 is tapped by two feed back pipes 13 and 14 spaced apart about 9 inches. The engine is a conventional 6 cylinder automobile engine of approximately hp. and with approximately 230 cu. inch capacity. The exhaust pipe is a standard 2 inch diameter pipe while the exhaust feedback pipes 13 and 14 are of slightly smaller diameter in the range of, for example, from 1 to 1% inches, in diameter. Feedback pipes 13 and 14 divert exhaust from the exhaust pipe 11 into a reservoir pipe 15 which is of diameter larger than the feedback for providing a reservoir or cavity for damping pressure variations in the feedback lines. A pipe of, for example, 2 /2 inches diameter can be used for the reservoir pipe 15. A return pipe 16 directs the feedback from reservoir pipe 15 back to the engine for reburning and in this example is connected at the carburetor 17 upstream from the carburetor inlet adjacent to the air filter 18. At this location upstream from the carburetor inlet adjacent to the air filter 18 the return pipe 16 directs the feedback exhaust above the throttle of carburetor 17 as illustrated in FIG. 2.

The conventional engine includes an air pump 20 driven by motor 21 which also drives fan 22. According to this embodiment, an air pipe 23 is connected to the outlet from air pump 20 for supplying air under pressure. The air pipe 23 terminates in branches 24 and 25 which are connected to the exhaust pipe 11 in juxtaposition with the feedback pipes 13 and 14 respectively.

In the arrangement of FIGS. 1 and 2, the first feedback pipe 13 taps the exhaust pipe 11 approximately 1% to 3 feet behind the engine block 12 while feedback pipe 14 is spaced approximately 9 inches beyond. Following the feedback pipes 13 and 14 the exhaust pipe 1 1 is reduced in diameter to, for example, 1 to 1% inches in diameter. This reduction in diameter increases the diversion of exhaust through the feedback pipe lines 13 and 14. With the dimensions of the pipe selected in the range of the described example, with the pipes arranged as described above and with the return pipe 16 connected upstream from the carburetor inlet adjacent to the air filter l8 liquid mufflerabove the throttle of carburetor 17 as illustrated in FIG. 2, a fractional portion of the exhaust in the range of approximately one half to two thirds of the exhaust is diverted into the reservoir pipe for recycling. The exhaust gas is diluted by air from air supply pipe 23 in the ratio of approximately 1:1.

While the return pipe 16 from reservoir pipe 15 is connected to the engine intake line upstream from carburetor 17 this return pipe can also be connected in a variety of other locations. Thus, the return pipe could also be connected downstream from the carburetor or to the engine intake manifold. In a preferred form of the invention the return pipe is connected to communicate directly through the engine cylinders to the combustion chambers.

To increase the cooling effect on the exhaust emission provided by the added piping and increased heat dissipation surface, one or more water jackets or heat exchangers can be provided around the exhaust path. In water cooled cars, the water jacket can be connected into the radiator and water cooling system. A back pressure valve can be provided in the exhaust pipe immediately downstream from the engine to prevent pressure buildup in the feedback line from affecting the engine.

A preferred embodiment of the invention in which the return pipe directs the exhaust air mixture directly through the cylinders and into the combustion chambers of the engine is illustrated in FIG. 3 and FIG. 3a. In this embodiment, the return pipe terminates in a plurality of branches 31 through 36 in number equal to the number of cylinders in the engine. Each of the terminal passageways 31 through 36 of the return pipe 30 communicates with the combustion chamber through a hole drilled in the top of the cylinders In conventional automobile engines the hole can be drilled above the spark plug. The invention is also applicable, however, for diesel engines and engines using fuel injection with the return pipe similarly 35 connected through the top of the cylinder into the combustion chambers. In FIG. 3 and FIG. 3a the remaining elements are numbered according to the corresponding elements of FIGS. 1 and 2 and element 12a designates the cover for the cylinder head and spark plugs. Each of the return passageways 31 through 36 communicates with the respective combustion chambers 37 through a back pressure valve 38, a standard one-way pressure valve, which is closed during combustion within the chamber and open during intake to permit the exhaust-air mixture to enter the combustion chambers along with the normal fuel-air mixture delivered from the intake manifold.

In combination with the exhaust feedback and recycling system the present invention also contemplates directing the exhaust pipe downstream from the feedback pipes through a liquid muffler-filter as illustrated in FIG. 4. The liquid mufflerfilter consists of a tank 40 with a suitable sealing 41 introducing the filter liquid which comprises a mixture of water and boiler compound such as, for example, a solution of one part DuBoth Boiler Water Treatment and nineteen parts water. In one example, a fifteen gallon tank was used with ten gallons of filter liquid formed by water and boiler compound as described above. The exhaust pipe 11 in the form of a downturned spout beneath the level 43 of the liquid 44 in the tank. By this expedient the exhaust is forced to bubble through the liquid converting carbon monoxide to carbon dioxide. Having passed through liquid 44 the gas is vented to the atmosphere through tail pipe 45 having an inlet 46 in the form of an upturned spout above the liquid level 43. The up-tumed spout allows only gas molecules to escape. To further prevent drainage of liquid from tank 44, a liquid actuated valve 47 of the conventional type can be placed in the tail pipe downstream from the tank to prevent escape of liquid while permitting free passage of gases.

It is apparent that a variety of dimensions, configurations, and arrangements can be used to achieve the present invention and provide variations in the extent of exhaust feedback, cooling, and air dilution with final filtering of the exhaust through the liquid muffler-filter. Thus, a plurality pf exhaust feedback pipes in number greater than 2 and in a variety of configurations can be used to increase mixture of the exhaust with air to increase cooling by increasing the exposed heat exchange surface area.

5 What is claimed is:

1. An exhaust feedback and control system for internal combustion engines of the type having a combustion chamber, an exhaust pipe, and an air pump comprising:

at least one feedback pipe connected at one end to the exhaust pipe for diverting fractional portions of the exhaust, and connected at the other end for delivering exhaust to the combustion chamber said feedback pipe connected directly to the engine combustion chamber through a back pressure valve;

and at least one air pipe connected at one end to the air pump outlet for supplying air under pressure and at the other end to the exhaust pipe in juxtaposition with said feedback pipe for diluting the feedback exhaust with air.

2. An exhaust feedback and control system as set forth in claim 1 wherein is provided an exhaust feedback reservoir means in the feedback line, said reservoir having a cross-sectional area greater than that of the feedback pipe for damping variations of pressure in the feedback line.

3. An exhaust feedback and control system as set forth in claim 1 wherein said feedback pipe is connected to the engine intake at the carburetor.

4. An exhaust feedback and control system as set forth in claim 1 wherein said pipes are arranged to divert approximately one-half to two-thirds of the engine exhaust.

5. An exhaust feedback and control system as set forth in claim 1 wherein is provided at least one cooling jacket around a portion of the exhaust path.

6. An exhaust feedback and control system for internal combustion engines comprising:

an exhaust pipe;

a feedback pipe connected at one end to the exhaust pipe for diverting a fractional portion of the exhaust to the engine combustion chamber;

an air pump;

an air pipe connected at one end to the air pump outlet for delivering air under pressure at the other end to the exhaust pipe in juxtaposition with said feedback pipe connection; and

an exhaust reservoir in said feedback line comprising a cavity having greater cross-sectional area than said acceleration and pipe for damping pressure variations in the feedback exhaust.

7. An exhaust feedback and control system for internal 5 combustion engines comprising:

means for cooling the engine exhaust;

means for diluting the engine exhaust with air; feedback means for diverting a fractional portion of said exhaust and air mixture and directing said fractional portion directly into the engine combustion chamber;

feedback and one-way back pressure valve means coupled between said feedback means and the engine combustion chamber for preventing flow-out of exhaust from the combustion chamber during the power stroke.

8. An exhaust feedback and control system as set forth in claim 7 wherein is provided means for damping pressure variations in said feedback means.

9. An exhaust feedback and control system as set forth in 65 claim 7 wherein said fractional portion of exhaust comprises approximately one-half to two-thirds thereof.

10. An exhaust feedback and control system as set forth in claim 6 wherein said feedback means directs the exhaust and air mixture adjacent the carburetor into the engine intake.

11. An exhaust feedback control system for internal combustion engines of the type having a combustion chamber exhaust pipe, and an air pump comprising:

first and second feedback pipes, each connected at one end to the exhaust pipe for diverting fractional portions of the engine exhaust;

a feedback reservoir comprising a pipe to which said first and second feedback pipes are connected, said reservoir pipe having a cross-sectional area greater than the cross section area of said feedback pipes for damping variations in pressure;

a return pipe connected to said reservoir pipe for delivering the exhaust to the engine combustion chamber;

and an air pipe connected to the engine air pump for delivering air under pressure, said air pipe having first and second passages connected to the exhaust pipe in juxtaposition with said first and second feedback pipes, respectively, whereby the fractional portions of said exhaust diverted by the feedback pipes are diluted with air.

12. An exhaust feedback and control system as set forth in claim 11 wherein the exhaust pipe downstream from the feedback pipe is connected to a liquid muffler and filter comprising a tank of water and boiler compound, said exhaust pipe connected below the level of liquid in the tank, said tank provided with a tail pipe connected above the liquid level in the tank.

13. An exhaust feedback and control system as set forth in claim 11 wherein said return pipe is connected at the carburetor.

14. An exhaust feedback and control system as set forth in claim 11 wherein said return pipe is connected directly to the combustion chamber of the internal combustion engine.

15. A system for controlling exhaust emission in internal combustion engines having a plurality of combustion chambers, air exhaust pipe, and an airpump means comprising: i a plurality of feedback pipes each connected at one end to the exhaust pipe for diverting fractional portions of the exhaust, each said feedback pipe having a cross-sectional area less than the cross-sectional area of the exhaust pipe;

a reservoir pipe to which the other end of each feedback pipe is connected, said reservoir pipe comprising a cavity for damping variations in pressure in the exhaust feedback;

a return pipe for directing exhaust feedback from the reservoir pipe to the combustion chambers of the engine said return pipe formed with a plurality of passageways connected to communicate directly with the respective engine combustion chambers and with a plurality of back pressure valves one in each said return pipe passageway;

and means for diluting the feedback exhaust with air comprising an air supply pipe having at one end a plurality of passageways connected to the exhaust pipe in juxtaposition with said feedback pipes, said air supply pipe connected at its other end to the engine air pump.

16. A system for controlling exhaust emission as set forth in claim 15 wherein the pipe dimensions are proportioned so that the total fractional portion of diverted exhaust comprises approximately one-half to two-thirds of the exhaust and wherein said exhaust is diluted with air in the ratio of approximately 1:1.

17. A system for exhaust emission control as set forth in claim 15 wherein the exhaust pipe downstream from the feedback pipe is connected to a liquid muffler-filter comprising a tank having a liquid boiler compound-water mixture therein, said exhaust pipe connected to the tank below the liquid level in the tank and wherein a tail pipe is connected to the tank above the liquid level in the tank.

18. A system for controlling exhaust emission as set forth in claim 15 wherein the exhaust pipe is formed with a smaller cross-sectional area downstream from the feedback pipes. 

1. An exhaust feedback and control system for internal combustion engines of the type having a combustion chamber, an exhaust pipe, and an air pump comprising: at least one feedback pipe connected at one end to the exhaust pipe for diverting fractional portions of the exhaust, and connected at the other end for delivering exhaust to the combustion chamber said feedback pipe connected directly to the engine combustion chamber through a back pressure valve; and at least one air pipe connected at one end to the air pump outlet for supplying air under pressure and at the other end to the exhaust pipe in juxtaposition with said feedback pipe for diluting the feedback exhaust with air.
 2. An exhaust feedback and control system as set forth in claim 1 wherein is provided an exhaust feedback reservoir means in the feedback line, said reservoir having a cross-sectional area greater than that of the feedback pipe for damping variations of pressure in the feedback line.
 3. An exhaust feedback and control system as set forth in claim 1 wherein said feedback pipe is connected to the engine intake at the carburetor.
 4. An exhaust feedback and control system as set forth in claim 1 wherein said pipes are arranged to divert approximately one-half to two-thirds of the engine exhaust.
 5. An exhaust feedback and control system as set forth in claim 1 wherein is provided at least one cooling jacket around a portion of the exhaust path.
 6. An exhaust feedback and control system for internal combustion engines comprising: an exhaust pipe; a feedback pipe connected at one end to the exhaust pipe for diverting a fractional portion of the exhaust to the engine combustion chamber; an air pump; an air pipe connected at one end to the air pump outlet for delivering air undEr pressure at the other end to the exhaust pipe in juxtaposition with said feedback pipe connection; and an exhaust reservoir in said feedback line comprising a cavity having greater cross-sectional area than said acceleration and pipe for damping pressure variations in the feedback exhaust.
 7. An exhaust feedback and control system for internal combustion engines comprising: means for cooling the engine exhaust; means for diluting the engine exhaust with air; feedback means for diverting a fractional portion of said exhaust and air mixture and directing said fractional portion directly into the engine combustion chamber; feedback and one-way back pressure valve means coupled between said feedback means and the engine combustion chamber for preventing flow-out of exhaust from the combustion chamber during the power stroke.
 8. An exhaust feedback and control system as set forth in claim 7 wherein is provided means for damping pressure variations in said feedback means.
 9. An exhaust feedback and control system as set forth in claim 7 wherein said fractional portion of exhaust comprises approximately one-half to two-thirds thereof.
 10. An exhaust feedback and control system as set forth in claim 6 wherein said feedback means directs the exhaust and air mixture adjacent the carburetor into the engine intake.
 11. An exhaust feedback control system for internal combustion engines of the type having a combustion chamber exhaust pipe, and an air pump comprising: first and second feedback pipes, each connected at one end to the exhaust pipe for diverting fractional portions of the engine exhaust; a feedback reservoir comprising a pipe to which said first and second feedback pipes are connected, said reservoir pipe having a cross-sectional area greater than the cross section area of said feedback pipes for damping variations in pressure; a return pipe connected to said reservoir pipe for delivering the exhaust to the engine combustion chamber; and an air pipe connected to the engine air pump for delivering air under pressure, said air pipe having first and second passages connected to the exhaust pipe in juxtaposition with said first and second feedback pipes, respectively, whereby the fractional portions of said exhaust diverted by the feedback pipes are diluted with air.
 12. An exhaust feedback and control system as set forth in claim 11 wherein the exhaust pipe downstream from the feedback pipe is connected to a liquid muffler and filter comprising a tank of water and boiler compound, said exhaust pipe connected below the level of liquid in the tank, said tank provided with a tail pipe connected above the liquid level in the tank.
 13. An exhaust feedback and control system as set forth in claim 11 wherein said return pipe is connected at the carburetor.
 14. An exhaust feedback and control system as set forth in claim 11 wherein said return pipe is connected directly to the combustion chamber of the internal combustion engine.
 15. A system for controlling exhaust emission in internal combustion engines having a plurality of combustion chambers, air exhaust pipe, and an airpump means comprising: a plurality of feedback pipes each connected at one end to the exhaust pipe for diverting fractional portions of the exhaust, each said feedback pipe having a cross-sectional area less than the cross-sectional area of the exhaust pipe; a reservoir pipe to which the other end of each feedback pipe is connected, said reservoir pipe comprising a cavity for damping variations in pressure in the exhaust feedback; a return pipe for directing exhaust feedback from the reservoir pipe to the combustion chambers of the engine said return pipe formed with a plurality of passageways connected to communicate directly with the respective engine combustion chambers and with a plurality of back pressure valves one in each said return pipe passageway; and means for diluting the feedback exhaust with air comprising an air supply pipe having at one end a plurality of passageways connected to the exhaust pipe in juxtaposition with said feedback pipes, said air supply pipe connected at its other end to the engine air pump.
 16. A system for controlling exhaust emission as set forth in claim 15 wherein the pipe dimensions are proportioned so that the total fractional portion of diverted exhaust comprises approximately one-half to two-thirds of the exhaust and wherein said exhaust is diluted with air in the ratio of approximately 1:1.
 17. A system for exhaust emission control as set forth in claim 15 wherein the exhaust pipe downstream from the feedback pipe is connected to a liquid muffler-filter comprising a tank having a liquid boiler compound-water mixture therein, said exhaust pipe connected to the tank below the liquid level in the tank and wherein a tail pipe is connected to the tank above the liquid level in the tank.
 18. A system for controlling exhaust emission as set forth in claim 15 wherein the exhaust pipe is formed with a smaller cross-sectional area downstream from the feedback pipes. 